Lighting calculator



FIG. 1 is a top, right perspective view of a lighting calculator showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a front elevational view thereof. 

The ornamental design for a lighting calculator, as shown and described. 